Cryptocurrencies have a funny sort of value as a kind of collectable like art. Similarly to how people may like to buy paintings, have them appreciate in value and maybe trade them to other art collectors, other people may like to collect bitcoins or similar to likewise have them appreciate and maybe trade to other bitcoiners. You could say it's illusory but if it makes people happy does it matter? I mean we'll all be gone in the end so if it helps you enjoy the journey.